Features Aircraft Innovations
A Perfect Combination

All of Bell is on a mission,” says Barry Kohler, the Montreal native who took over in January as president of Bell Helicopter Textron Canada. “ Our mission,” he says, “ is to enable each of our customers to succeed. Everyone on the Bell team is committed to that, and the 429 is the best example of that commitment.”

Bell Helicopter’s 412EP is a robust, reliable medium-lift helicopter with a solid reputation for performing a wide variety of utility missions offshore and on shore.

Among the 1,500 employees in and around the Mirabel plant, the enthusiasm – from the boardroom down to the shop floor – for the new 429 and the veteran 412 Enhanced Performance (EP) is evident. The consensus is the purchase of both IFR-capable machines would be the perfect combination for the Canadian Coast Guard (CCG). And while the CCG has yet to formally commit funds and enter bids for renewal of its 22 aging aircraft, Gary Sidock, director general, Fleet Directorate, is well aware a change is on the horizon, given the age of the aircraft ranges between 25 to 37 years.

The light, twin-engine 429 was certified for flight by Transport Canada as recently as July 2009, while the medium, twin-engine 412EP has proven itself to be the workhorse in some of the harshest environments around the world, from offshore support to disaster-relief missions, including most recently in earthquake-stricken Haiti and Chile.

Bell 412EP: A Closer Look
Like all civil Bell helicopters, the 412EP (Enhanced Performance) is manufactured by Bell in and around Mirabel, while its PT6T-3D twinned turboshaft engine is built by Pratt & Whitney Canada in Longueuil, Que. Key components like the drive train and rotor blades do come from Bell in Fort Worth, Texas, but the Mirabel operation is supported by more than 100 other Canadian companies.

The Bell 429 recently flew to a Coast Guard lighthouse in the St. Lawrence River just east of Quebec City.

Chile’s air force operates the Bell 412EP for search and rescue, aid missions and general troop transport. It currently has six 412EPs in service and six more are scheduled for delivery.

The CCG presently operates the Bell 212, from which the 412EP was derived. Both aircraft are designed to carry 14 passengers, though the Coast Guard configuration is for nine in the 212. The 412EP has all the advantages of the 212 – like the large cabin, payload, performance – but much, much more. While the 212’s designed useful load is 2,261 kilograms (4,985 pounds), for instance, the 412EP can carry 2,313 kg (5,100 lb.). Partially because of its four-bladed main rotor and higher transmission ratings, the 412EP outperforms its predecessor. It has a maximum cruise speed of 226 kilometres per hour (122 knots) versus 185 km/h for the 212 and a range of 659 km (356 nautical miles) to the 212’s 424 km.

The 412EP will climb at nine metres per second (1,780 feet per minute), 2.2 metres per second faster that the 212. Its service ceiling is 4,968 m (16,300 ft.) compared to the 212’s 3,932 m (12,900 ft.). The 412EP hover-in-ground-effect (HIGE) ceiling is 3,109 m (10,200 ft.) on a standard day at its maximum gross weight (MGW) of 5,398 kgs (11,900 lb.). That’s more than double the 212’s HIGE ceiling of 1,448 m at a 318-kg-higher MGW.

“The 412EP offers the CCG more performance and speed than the current 212,” says Dennis Lacroix, director of marketing at Bell Helicopter Textron, “and a bigger cabin and useful load than other contenders for the medium-lift mission. In addition, the 412EP would simplify the Coast Guard’s introduction of a new medium-lift helicopter by virtue of commonality in the training, tooling and spares also used for the 212.”

While Bell does not currently offer a glass cockpit for the 412EP, such flight instrumentation is available today as retrofits under supplemental type certificates. The Bell 412EP would extend medium-lift capabilities that Coast Guard crews and passengers are already familiar with.

A Strong Companion: Bell 429
In February 2010, when helicopter search-and-rescue (SAR) firm Priority 1 Air Rescue was selecting a machine that would demonstrate maximum hoist rescue in a SAR configuration, it went to Mirabel for the 429.

Textron Canada Ltd. had successfully completed the design engineering and Human External Cargo (HEC) load flight testing on a new 429 in a search-and-rescue (SAR) configuration. Pleased with what he saw, Priority 1 Air Rescue president Brad Matheson stated, “The Bell 429 is very well suited for search-and-rescue and multi-mission emergency response and possesses two exceptional operational attributes. The aircraft has a very large cabin and a well-placed hoist boom mount that allows the hoist system operator to safely transition patient litters or SAR personnel into the cabin door with minimal effort and time. Secondly, there also exists a very predictable and stable rotor wash below the aircraft while hoisting, which makes the rescue specialist’s job safer and easier.”

With such an endorsement, the Bell 429 helicopter is well positioned as a major contender in the SAR aviation market.

Certified as a single-pilot instrument flight rules (SPIFR), Category A helicopter, the 429 is a reflection of Bell’s commitment to its customers. As it began to design the 429, Bell asked customers what they wanted. Pilots said they wanted an aircraft easy and fun to fly. It had to be manoeuvrable, be equipped to enhance their situational awareness and reduce pilot workload.

The 429 has a maximum cruise speed of 278 km/h (150 knots) at its maximum gross weight (MGW) (internal) of 3,175 kg (7,000 lb.) and sea level (at International Standard Atmosphere). Its two Pratt & Whitney Canada PW-207D1s provide plenty of power. Each has a rated take-off power of 446 kilowatts (598 shaft horsepower), and the 429’s transmission rating of both maximum continuous power and five-minute is 820 kilowatts (1,100 shaft horsepower). With an advanced rotor design, when compared with other light twins, the 429 has more than 30 per cent greater climb rate at MGW from sea level on a standard day, almost 20 per cent more useful load at altitude on a hot day and roughly 10 per cent faster speed at MGW.

“The rotor is quiet,” says Pete Ranger, a Bell experimental test pilot in Mirabel who has been on the 429 program since its start. “It doesn’t seem to require a lot of power to go fast and it does not care if it’s at 20,000 feet or sea level at -40 C or at max temperatures. There’s no ride change whatsoever.”

Governments around the world recognize the 412EP’s value in performing national missions. In December 2009, Mexico took delivery of five 412EPs for counterdrug and other homeland security missions and has three more on order.

The 429’s service ceiling at 3,175 kgs on a standard day is 5,704 m (18,714 ft.). Its hover ceiling in ground effect at that weight is 4,307 m (14,132 ft.) and its out-of-ground-effect hover ceiling is more than 3,413 m (11,200 ft.). The useful load (internal) is 1,140 kg (2,513 lb.) in standard configuration.

Within is evidence that Bell listened to the people who would be operating the machine: the pilots. The 429 flight deck’s “Open Architecture” software, the intuitive instrument layout, the excellent visibility and overhead clear of breakers, all reduce pilot workload and enhance situational awareness.

“The cockpit is a full glass interface, with everything at the pilot’s reach without any major head movement,” Ranger says. “ There are no breakers to deal with and nothing on the roof other than a map light and a rotor brake handle that you would obviously not require until you are back on the ground, where major head movements would no longer be critical.”

A good example of pilot workload reduction is the glass cockpit’s Power Situation Indicator. “This integrated display,” explains Ranger, “presents all the parameters the 429 pilot needs to manage power from the engines and their effect on the rotor. These include engine torques and combined engine torque, engine measured gas temperatures and gas turbine speeds, engine power turbine speeds, rotor speed and rotor governing reference speed. It also provides timers for time-limited zones (OEI and take off).”

Neil Marshall, Bell’s 429 program manager at Mirabel, says careful planning in the design phase was paramount in creating a comfortable, yet durable, aircraft. “When we surveyed customers early in the design phase, those who work in the back said they wanted a cabin that was big and comfortable to work in and versatile enough to handle a variety of missions,” he says.

The 429 combines a sturdy design with extensive use of composite materials to produce a spacious, open cabin with the volume of an intermediate twin in a light twin frame. The cabin has room for up to six passengers and a seventh on the flight deck and a flat, level floor that makes it easy to load and unload through wide side doors or optional clamshell doors aft. Its volume (not including the cockpit) is 3.7 cubic m (130 cubic ft.) and the baggage compartment is 2.1 cubic m (74 cubic ft.), for a total volume for cargo of 5.8 cubic m (204 cubic ft.). Due in part to the tougher airworthiness requirements under which it was certified, the 429 is designed to withstand forces 50 to 300 times greater than competing light twins. (As a result of those rules, the 429 also uses energy-attenuating seats in the cockpit and the cabin.)

The 429 also uses a patented transmission-mounting system called LIVE (liquid inertial vibration eliminator) that passively minimizes vibration from the main rotor into the cabin. It is a key part of a multi-layered approach to vibration control that produces what is arguably the smoothest ride in the helicopter world.

Cost Conscious
In these cost-conscious times, customers told Bell they wanted a new light twin that helped them manage the bottom line. Bell listened and integrated this into the design. The 429 is the first, and, so far, the only. helicopter designed using the Maintenance Steering Group 3 (MSG-3) process that has been the foundation of airliner reliability since 1970. Using this process, lead mechanics from the customers, representatives of Transport Canada, the FAA and EASA, and Bell engineers were involved from the start and were able to steer the direction of the design, says Marshall. From the routing of systems to the placement and size of maintenance panels, this group has helped develop an aircraft that is more efficient and easier to maintain. One result is that all of the 429’s systems are routed outside of the cabin, either above the roof beams or below the floor structure. The interior of the 429 does not need to be removed during an annual inspection, Marshall pointed out – and that cuts time and costs.

Based on post-certification component testing and the strength of its maintenance program, Bell has already issued two revisions of the 429’s maintenance program. It cut the number of life-limited parts on the helicopter by more than half, from 87 to 43, significantly reducing direct maintenance costs while fully retaining the light, twin-engine helicopter’s safety and reliability.

Finally, both helicopters come as part of an extensive technical and customer support organization. Bell’s own organization and a network of 23 customer service facilities in Canada, from North Saanich, B.C., to Goose Bay, N.L., are already in place to provide swift support of CCG aircraft from coast to coast to coast. With such a network and such a combination, Bell feels it is well positioned to satisfy CCG requirements.